In a Pleasant Valley Middle School classroom, Sarah Jones explained to her students the difference between a synonym and homonym, cracked jokes, dropped random facts about the human brain, administered a quiz and demonstrated how to write a cohesive paragraph.

In a Pleasant Valley Middle School classroom, Sarah Jones explained to her students the difference between a synonym and homonym, cracked jokes, dropped random facts about the human brain, administered a quiz and demonstrated how to write a cohesive paragraph.

Not bad for a substitute teacher — who turns 90 in March.

Jones, who has been teaching for almost 70 years, is something of a celebrity in the Pleasant Valley School District.

She's known for her deep knowledge of a range of subjects, her ability to connect with students and the many facts and figures she can rattle off.

She says she still teaches because it energizes her. She loves seeing that she's ignited a child's curiosity. And in her second-period English class Wednesday, she offered many reasons to be interested.

"Did you know that by the time you guys graduate from high school you'll probably have about 50,000 words in your vocabulary?" she asked the eighth graders.

Though the focus of the day should be on writing an effective paragraph, Jones wanted to discuss other aspects of the English language.

"Anyone know what the shortest sentence in the English language is? 'I am.' Or ever think about how many times we use the word 'up' in the English language?"

One student calls out: "Listen up."

Another says, "Hold up," yet another says, "Giddy up."

Not to be outdone, Jones says: "I hope the rain holds up. You know, so it doesn't come down."

"Oh come on," groan the students at the pun. Nevertheless, she's got their attention.

Jones, a native of Pen Argyl and a graduate of East Stroudsburg University, started her career in the East Stroudsburg Area School District.

She retired as a full-time teacher in 1987 at Pleasant Valley and began subbing in 1990.

She never got a master's degree but did a lot of studying on her own, which is why she knows a lot about many subjects.

"When I was here as a rookie teacher about 30 years ago, she was the teacher to look up to. And it's amazing that she still is that kind of person," said Michael Kello, assistant middle school principal.

And Kathy Smith, an administrative assistant, said that her kids, who are students in the district, "always love to get (Jones) off topic, because she has so many interesting stories to tell."

Back in the classroom Wednesday, Jones has just given out a quiz.

Almost all of the students are silent. Some act up, but Jones quickly spots them.

She walks over to a student who has several small folded pieces of paper on his desk and a rubber band he's using as a sling shot.

The student already fired one piece of paper across the classroom using the rubber band.

"Can I have your dangerous weapon?" she asks.

And then referring to the small pieces of paper: "I'll take the ammunition, too." The class erupts in laughter.

Jones says she wants to go on substituting for as long as she can.

"If I wasn't doing this, I'd be just sitting at home," she said.

She has outlived her two children and her husband and says that being in the school invigorates her.

She says she has managed to adapt somewhat to a high-tech society and tries to stay on top of the news.

She knows some text-messaging shorthand and knows exactly why and how Heath Ledger died.

Still, she believes technology makes learning less personal. Either way, she gets through to the kids.

One student at the back of the class who at some points was talking out of turn still said he admired the woman at the head of the class.